Such a method and the corresponding equipment are known from state of the art implementations for connecting a computer to communications networks, such as the internet. As an example, the assignee of the present invention distributes a product called PSS (Personal Service Selector) which uses at least two network adapters installed in a machine to provide access to a plurality of communications networks. The adapters may be either hardware adapters, such as Ethernet cards, or software implemented adapters, such as PPPoE adapters (Point-to-Point-Protocol over Ethernet). Likewise, there are operating systems for network client terminals, which operating systems are capable of dealing with a plurality of network adapters.
In the prior art systems, only one routing table is implemented in the machine. The routing table is some sort of a look-up table which is used by all network adapters in the decision process where an information packet has to be sent to next. The routing table typically comprises a plurality of line entries, each of which defining routing particulars for a certain destination or group of destinations. An example of a typical routing table, as it is used in prior art systems, is shown in FIG. 2 for illustrative purposes.
Each line entry typically comprises a destination address field and a mask field, the combination of which identifies a predefined destination or group of destinations. For each identified destination or group of destinations, a so-called next hop field and an interface field define where the information packets (the traffic) has to be relayed to. The next hop field defines the next intermediate destination on the way to the final targeted destination, the interface field defines the interface which is to be used on this route, for instance the network adapter to be used. Based on the entries in the routing table, the traffic is relayed along the route that provides the best match between the targeted destination and the predefined destinations identified in the destination and mask entries.
Typically, the routing table includes one default route which is chosen when no better match can be found among the specified destination entries (referred to as default situation in the following). If a plurality of destinations should be accessible along predefined routes and/or if for a specific destination different routes should be provided, a plurality of corresponding routing entries has to be included in the routing table. This applies particularly to cases, where different destinations should be reached simultaneously via different network adapters. However, the management of these entries becomes very complex when a network adapter is not statically configured for a specific destination or group of destinations. In addition, detailed knowledge about the network topology is required to establish an appropriate routing table in such a scenario.